Astronauts’（宇航員的） footprints（腳印） stay on the moon forever（永遠(yuǎn)地）. There’s no wind to blow them away.

You have about 300 bones（骨頭） when you are born（出生）. You have only 206 when you grow up.

You can’t breathe（呼吸） and swallow（吞咽） at the same time.